Rocker arm adjusters

Posted By: Bill MeLater

Rocker arm adjusters - 01/27/09 05:52 PM

Think I'll be ok with three threads showing on my adjusters? Isky ductile's w/.579 lift ft solid w/380# over the nose. Why does everyone reccomend only one thread exposed? Is it for structural or oiling purposes or a combination of both? My geometry looks perfect and I don't want to have to buy new pushrods....Again

Posted By: AndyF

Re: Rocker arm adjusters - 01/27/09 06:24 PM

The longer the stud hangs out under the rocker arm the more sideways motion that the pushrod does. So you lose some effective lift with a longer adjuster. Also, the force on the adjuster goes way up since there is a longer lever arm trying to break it off in the rocker arm. Depending on the rocker arm design, the oiling can also suffer. Some rocker arms use a little piddle hole right at the adjuster to spray oil into the cup. If the cup isn't in the right location then the oil can't spray in.

Posted By: MR_P_BODY

Re: Rocker arm adjusters - 01/27/09 06:30 PM

Quote:

Think I'll be ok with three threads showing on my adjusters? Isky ductile's w/.579 lift ft solid w/380# over the nose. Why does everyone reccomend only one thread exposed? Is it for structural or oiling purposes or a combination of both? My geometry looks perfect and I don't want to have to buy new pushrods....Again

The greater it sticks out the more side load you
put on the adjuster when its at lift. Plus if you
were to lay a straight edge across from the valve
tip surface thru the centerline of the shaft area
you would see that the other end would be right at
the edge of the rocker, that would be thew ideal
point for the adjuster to be. Also the higher the
rocker ratio the worse this condition will be(the
threads sticking out)

Posted By: Bill MeLater

Re: Rocker arm adjusters - 01/27/09 08:30 PM

Ok, I see the additional leverage as a potential problem. I'm not clear on how this can affect my rocker ratio though. Is it because it appears to move the pushrod cup closer to the shaft centerline? They are 1.5's with relatively light spring pressures and I won't be spinning it past 6200, do you guys think I can get a season out of it like it is or am I just asking for trouble?

Posted By: Cab_Burge

Re: Rocker arm adjusters - 01/27/09 08:47 PM

I have used the Isky ductile iron rockers in simialr applications as yours, you will be fine

If you can use a set of lash caps they will help move the adjusters up into the rockers a thread and a half or so, if your really worried about that

Posted By: Bill MeLater

Re: Rocker arm adjusters - 01/27/09 09:02 PM

Thanks Cab, that's exactly the answer I was hoping for. I just wiped a cam in November (on break in no less) and I really don't have much money left to throw around. I just ordered .080 lash caps from my local speed shop yesterday, the three threads showing is with an .080 (+ lash) feeler guage at the stem. I'm gonna finish screwing it together this weekend and throw it on the stand, hopefully break it in the following weekend. Thanks for all the help and wish me luck.

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